add custom 404 page

src/pages/404.astro

@@ -0,0 +1,13 @@
+---
+import { useTranslations } from '@/i18n/utils'
+import BaseLayout from '@/layouts/BaseLayout.astro'
+
+const { lang } = Astro.params
+const t = useTranslations(lang)
+---
+
+<BaseLayout title="Страница не нейдена">
+  <div class="flex h-full w-full items-center justify-center">
+    <h1>{t('404.title')}</h1>
+  </div>
+</BaseLayout>